Invalid lifting seat

ABSTRACT

A powered seat which assists an invalid in moving between seated and standing positions, under full control of the invalid. The structure is adaptable to various configurations of a chair, or to an attachment for a toilet without requiring any modification of the toilet itself. The seat is hinged in such a manner that the invalid is raised or lowered almost vertically, with no danger of sliding off the seat.

United States Patent [72] Inventor Gordon L. Condon La Mesa, Calif. [2]]Appl. No. 852,429 [22] Filed Aug; 22, 1969 [45] Patented Nov. 30, 1971[73] Assignee lnvalift Incorporated [541 INVALID LlF'llNG SEAT 1 Claim,8 Drawing Figs.

[52] US. Cl. 4 297/330, 297/335, 297/DIG. 10 [51] Int. Cl A47c 1/00 [50]Field of Search 297/330, DlG. 10,332, 334, 335, 337-339, 333, 3 l 3,326; 5/76 [56] References Cited UNITED STATES PATENTS 974,769 11/1910Hoff 297/332 Primary Examiner Francis K. Zugel Attorney-Carl R. BrownABSTRACT: A powered seat which assists an invalid in moving betweenseated and standing positions, under full control of the invalid. Thestructure is adaptable to various configurations of a chair, or to anattachment for a toilet without requiring any modification of the toiletitself. The seat is hinged in such a manner that the invalid is raisedor lowered almost vertically, with no danger ofsliding ofi the seat.

PATENTEU NOV30 1971 SHEET 1 OF 3 SI/TG 3 I NVENTOR.

GORDON L. CONDON Fig. 2

ATTORNEY PATENTED NIB/3019?! 34623767 SHEET 3 UF 3 Fig.7

IIO

INVENTOR. GORDON L. CONDON F|g.8

ATTORNEY INVALID LIFTING SEAT BACKGROUND OF THE INVENTION Various typesof powered lifting seats have been devised to assist persons who havephysical disabilities which cause loss of strength in arm and legmuscles. Such seats are usually hinged at the front and tilt upward andforward, there being little actual lifting support at high angles ofinclination. Mechanisms normally used, such as hydraulic or screwjacks,are complex and occupy considerable space below the seat, which imposesrestrictions on structure and uses of the seat.

SUMMARY OF THE INVENTION My lifting seat is hinged at the rear and has avery simple lifting mechanism which is primarily contained in the sideor leg structure of the seat assembly. The forward edge of the seat isdownwardly curved and, in the raised position, provides a nearhorizontal platform which offers maximum support for a person, who isessentially standing at that position. In one embodiment the mechanismis arranged so that a seat unit can be fitted over a conventionaltoilet, without alteration of the toilet and with a minimum of change inseat height. Operation of the seat is under full control of the occupantand motion stops instantly when the control is released.

Other objects and many advantages of this invention will become moreapparent upon a reading of the following detailed description and anexamination of the drawings, wherein like reference numerals designatelike parts throughout and in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a toiletadaptation of the seat.

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1.

FIG. 3 is an enlarged sectional view taken on line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.

FIG. 5 is an enlarged sectional view showing attachment of the drivingstraps to the drive shaft.

FIG. 6 is a wiring diagram of the control means.

FIG. 7 is a sectional view similar to FIG. 2, but showing the adaptationof the mechanism to an armchair.

FIG. 8 is a top plan view of the armchair, with a portion of the seatcut away.

DESCRIPTION OF THE PREFERRED EMBODIMENT The seat structure shown-in FIG.1 through 4 is made to fit over a conventional toilet 10 indicated inbroken line in FIG. 4. The seat assembly has a pair of hollow boxlikcsides 12 and 14, which form the supporting legs and are interconnectedby a crossbar 16 at the upper rear comers. A seat 18 is attached tocrossbar 16 by a hinge 20 to swing upwardly and rearwardly, the seatresting on top of sides 12 and 14 in the down position. The forwardportion 22 of seat 18 is curved downwardly to allow the legs to extendcomfortably, the upper edges of the sides being correspondingly curvedto support the entire side edge portions of the seat. Fixed to oppositesides of the seat 18 are arms 24 and 26 of any convenient configuration,the arms preferably being hollow to contain pushbuttons 28 and 30 inopposed relation on the inside of the forward portions of the arms.

Sides 12 and 14 are similar in structure, each having an outer wall 32and an inner wall 34, with a front panel 36 and a rear panel 38connecting the walls. The base is enclosed by a bottom panel 40 to whichglide buttons or similar feet 42 are secured.

Fixed to the underside of seat 18 at each side edge is an arcuatequadrant 44 having its center of radius at the axis of hinge 20, thequadrant being contained in the hollow side element. At the upper rearcorner of the structure is a transverse drive shaft 46 parallel tocrossbar l6 and coupled at one end to a low-speed gear motor 48, whichis mounted on the outside of side 14. Drive shaft 46 is enclosed in asleeve 50 extending between sides 12 and 14 and secured to their innerwalls 34 by flanges 52, which adds structural support to the assembly.In the upper rear position the drive shaft passes above the back portionof the toilet l0, behind the existing seat 54 and is the only structurebeneath the seat, other than crossbar 16. This allows seat 18 to fitvery closely over the top of toilet seat 54, with a minimum of increasein seat height, the seat 18 having an opening 56 corresponding to thatof the toilet seat.

Each end portion of drive shaft 46 between walls 32 and 34 has a fiat 58to which one end of a strap 60 is fastened by means of a washer plate 62and one or more screws 64, as in FIG. 5. The strap 60 is of strong wovenfabric capable of supporting the weight of a person on the seat. Eachstrap 60 extends down to a guide roller 66 at the bottom rear of theside structure and forward along the bottom to a guide roller 68 at thefront of the structure to clear quadrant 44. The strap then extendsupwardly over a support roller 70 at the top of the side structure justforward of the quadrant and is carried around the arcuate surface of thequadrant, the other end 72 of the strap being fixed in a suitable mannerto the rear of the quadrant. When drive shaft 46 is rotated to retractor roll up the strap around itself, the quadrant 44 is pulled forwardlyand upwardly causing the seat 18 to be raised as in the broken lineposition in FIG. 2.

A simple control circuit for the seat is shown in FIG. 6. Motor 48 isconnected to the moving contacts 74 of a double pole, double throwswitch 76, which has a pair of up contacts 78, 79 and down contacts 80,81. Switch 76 is shown installed in the outside of arm 26, but could beat some other convenient location. From a convenience plug 82 electricalpower is supplied to contacts 78 and 80 through pushbuttons 28 and 30 inseries. The other side of the electrical power supply is connecteddirectly to contact 81, and to contact 79 through a normally closedlimit switch 84. With switch 76 in the up position, as in full line,closure of both pushbuttons 28 and 30 will complete the circuit to motor48 and cause the seat to be raised. At the upper end of the travel thelimit switch 84, which can be in any convenient location in thestructure, will be opened and the motor will stop. To lower the seat theswitch 76 is moved to the down position, indicated in broken line, sothat closure of pushbuttons 28 and 30 will actuate the motor in reverseand extend or unwind the straps. A limit switch is not essential in thedown position, since an overrun will only result in slackening of thestraps, which is not a problem.

When the seat rises, the occupant is lifted almost vertically, ratherthan pushed forward and the heels tend to slide back toward the seatuntil the occupant is in a standing position. At the upper end of thetravel the forward seat portion 22 fonns a substantially horizontalplatform, as shown in FIG. 4, supporting a person until walking aids canbe reached. The clear frontal space between the sides of the seat allowsfree motion of the feet to a safe standing position.

In the form shown in FIG. 7 and 8, the structure is adapted to anarmchair. Since it is not necessary to provide clearance for a toilet,the drive means can be simplified, but the action is the same. The seatstructure comprises a pair of hollow sides 86 and 88, similar to sides12 and 14, connected at the rear by a back 90. The seat 92 is attachedto back by a hinge 94 and rests on top of the sides. Fixed under theseat 92 are quadrants 96 extending down into sides 86 and 88 and havingstraps 98 secured to their lower rear portions. In this form a driveshaft 100 extends across the chair immediately below seat 92 and forwardof the quadrants, the straps 98 being secured to the drive shaft endsinside the hollow sides. Fixed between sides 86 and 88 below the driveshaft I00 is a platform 102, which supports a gear motor 104 coupled tothe drive shaft and adds rigidity to the structure of the chair. Aworm-drive-type motor is preferred to prevent slippage under load and toprovide a suitably slow drive speed. To facilitate removal of motor 104for servicing, the drive shaft is provided with detachable couplings 106of conventional type.

Seat 92 has a downwardly curved front portion 108 and has a similaraction to that described for seat 18. Arms 110 are secured to the sidesof the seat for comfort and to carry the actuating switches as describedabove. It should be understood that the structure shown is merely abasic frame and could vary considerably in configuration, withupholstery to suit. For added comfort in seating, the seat could beinclined downwardly to the rear. The front portion between the sides ispreferably left clear to allow a person's to come back directly belowthe front of the raised seat in a safe standing position.

In sitting down a person merely backs up to the raised seat and sits onthe horizontal front edge. When the seat is lowered the occupant willtend to move back over the curved edge onto the seat, as the knees bendor the feet slide forward. At any time the seat can be stopped instantlyfor body adjust ment, if necessary, and all motion is at a constantdriving rate.

Having described my invention, I now claim:

1. An invalid lifting seat comprising,

a pair of spaced side members having interconnecting means at the rearthereof,

a seat having a hinge connection to said interconnecting means to swingupwardly and rearwardly, said seat normally resting on said sidemembers,

said seat having a downwardly curved front portion which forms asubstantially horizontal platform in the raised position of said seat,

drive means coupled to said seat to raise and lower said seat at acontrolled rate,

said side members are hollow and said drive means is primarily enclosedin said side members,

said drive means includes substantially arcuate quadrants fixed belowsaid seat radial to the axis of said hinge and extending inside saidside members, flexible strap means attached to and extending around saidquadrants, and means for retracting and extending said strap means,

said means for retracting and extending said strap means includes amotor having a drive shaft with ends extending into said side members,said strap means being secured to and rolled around said drive shaftends,

said drive shaft is at the upper rear of the side members to pass abovea toilet over which said seat is positioned, and

support rollers mounted in the upper portions of said side membersforward of said quadrants, said strap means passing over said supportrollers to said drive shaft, and guide rollers mounted in the lowerportion of said side members guiding said strap means clear of saidquadrants.

1. An invalid lifting seat comprising, a pair of spaced side membershaving interconnecting means at the rear thereof, a seat having a hingeconnection to said interconnecting means to swing upwardly andrearwardly, said seat normally resting on said side members, said seathaving a downwardly curved front portion which forms a substantiallyhorizontal platform in the raised position of said seat, drive meanscoupled to said seat to raise and lower said seat at a controlled rate,said side members are hollow and said drive means is primarily enclosedin said side members, said drive means includes substantially arcuatequadrants fixed below said seat radial to the axis of said hinge andextending inside said side members, flexible strap means attached to andextending around said quadrants, and means for retracting and extendingsaid strap means, said means for retracting and extending said strapmeans includes a motor having a drive shaft with ends extending intosaid side members, said strap means being secured to and rolled aroundsaid drive shaft ends, said drive shaft is at the upper rear of the sidemembers to pass above a toilet over which said seat is positioned, andsupport rollers mounted in the upper portions of said side membersforward of said quadrants, said strap means passing over said supportrollers to said drive shaft, and guide rollers mounted in the lowerportion of said side members guiding said strap means clear of saidquadrants.